The radiation heat transfer mechanism is one of the significant problems in engineering. This problem is centered on the determination of the overall radiation interchange configuration factor. In the past, Hottel, Yagi-Kunii, Sparrow and Gebhart introduced the methods of calculating the overall configuration factor in the enclosure. But these methods have been too complicated for practical application, and are not suitable for making an accurate analysis and calculation. In this paper, a new method for determining the overall configuration factor within an enclosure filled with absorbing medium is described. Even if the enclosure is composed of a complicated shape and a number of surfaces, the conversion method expressed as a matrix form leads to a systematic and efficient solution of the overall configuration factor.